Sand Traps For Use In Oil And Gas Extraction Operations
A sand trap for oil and gas extraction includes a cyclonic flow section having a longitudinal axis, an inlet for receiving a high-pressure fluid stream with particulates, an upper portion, a choke area, and a funnel portion narrowing from the upper portion to the choke area. The inlet has an axis generally perpendicular but askew to the longitudinal axis. A vortex finder extends downwardly from a cap and defines a passageway coaxial with the longitudinal axis for fluid to exit. A spherical accumulator extends downwardly from the cyclonic flow section and has a center axis coaxial with the longitudinal axis. Upper and lower ends of the spherical accumulator each have an opening centered along the longitudinal axis, and the spherical accumulator is unobstructed from the upper opening to the lower opening for the particulates to pass unimpeded and accumulate in the accumulator.
This application claims priority to U.S. Application No. 63/106,768, filed Oct. 28, 2020, which is incorporated by reference in its entirety herein.
FIELD OF THE DISCLOSUREThe disclosure relates generally to the field of oil and gas extraction. More particularly, the disclosure relates to sand traps, also commonly referred to as sand separators, which are commonly used in oil and gas extraction for removing sand and particulates from fluid streams to prevent erosive damage to piping, valves, and pumping equipment.
SUMMARYThe following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented elsewhere.
According to an embodiment, a sand trap for use in oil and gas extraction operations has a hollow cylindrical wall, a cap, a vortex finder, a cyclonic insert, and a spherical accumulator. The hollow cylindrical wall has upper and lower ends and a longitudinal axis extending generally vertically, and the hollow cylindrical wall has an inlet opening for receiving a high pressure fluid stream with particulates. The inlet opening has an axis generally perpendicular but askew to the longitudinal axis of the hollow cylindrical wall. The cap is selectively secured over the hollow cylindrical wall. The vortex finder extends downwardly from the cap and defines a passageway for fluid to exit. The passageway is coaxial with the longitudinal axis of the hollow cylindrical wall. The cyclonic insert is inside the hollow cylindrical wall and has a generally cylindrical upper portion, a choke area, and a funnel portion that narrows from the upper portion to the choke area. The generally cylindrical upper portion has an inlet that is at least as big as the inlet opening and is configured to align with the inlet opening to allow uninterrupted flow into the cyclonic insert. The spherical accumulator extends downwardly from the hollow cylindrical wall and has upper and lower ends and a center axis that is coaxial with the longitudinal axis of the hollow cylindrical wall. The spherical accumulator upper end has an upper opening centered along the longitudinal axis of the hollow cylindrical wall, and the spherical accumulator lower end has an exit opening centered along the longitudinal axis of the hollow cylindrical wall. The spherical accumulator is unobstructed from the upper opening to the exit opening such that the particulates are allowed to pass unimpeded and accumulate in the accumulator.
According to another embodiment, a sand trap for use in oil and gas extraction operations includes a cyclonic flow section, a cap over the cyclonic flow section, a vortex finder, and a spherical accumulator. The cyclonic flow section has a longitudinal axis, an inlet opening for receiving a high pressure fluid stream with particulates, a generally cylindrical upper portion, a choke area, and a funnel portion that narrows from the upper portion to the choke area. The inlet opening has an axis generally perpendicular but askew to the longitudinal axis. The vortex finder extends downwardly from the cap and defines a passageway for fluid to exit. The passageway is coaxial with the longitudinal axis. The spherical accumulator extends downwardly from the cyclonic flow section and has upper and lower ends and a center axis that is coaxial with the longitudinal axis. The spherical accumulator upper end has an upper opening centered along the longitudinal axis, the spherical accumulator lower end has an exit opening centered along the longitudinal axis, and the spherical accumulator is unobstructed from the upper opening to the exit opening such that the particulates are allowed to pass unimpeded and accumulate in the accumulator.
Fluid streams in oil and gas extraction operations are often under high pressure and carry significant amounts of solids, including sand and other particulates. The sand and particulates are erosive, and improved devices are needed to separate them from the fluid.
The skid 110, shown in
The cylindrical shell 120 is positioned above the accumulator 150 and has upper and lower ends 120a, 120b and a longitudinal axis 120′ that extends generally vertically. As shown in
A flange (or “cap”) 124 is configured to be removably secured atop the flange 123 (e.g., by bolts 124a or other appropriate fasteners), and a vortex finder 125 is coupled to the flange 124 such that the vortex finder 125 extends along the longitudinal axis 120′ when the flange 124 is secured to the flange 123. The vortex finder 125 has open upper and lower ends 125a, 125b, with the open upper end 125a being configured for attachment to outlet piping. In some embodiments, the vortex finder 125 may be a single piece of pipe; in other embodiments, the vortex finder 125 may be formed of multiple pieces of piping and/or part of the cap 124. For example, the vortex finder 125 may be formed of a piece of pipe extending below the cap 124, a passageway in the cap 124, and another piece of pipe extending above the cap 124.
The cylindrical wall 122 has an inlet opening 126 (
Focus is now directed to the cyclonic insert 130, shown in
It may be desirable for at least one support (or “stabilizer”) 133 to extend from the choke area 132c to the inner face 122c of the cylindrical wall 122 to stabilize the choke area 132c when the sand trap 100 is in use. The support 133 may be annular, a rod, or any other suitable shape. In some embodiments, it may be particularly desirable for the support 133 to meet the inner face 122c of the cylindrical wall 122 where the outer face 122d of the cylindrical wall 122 meets the accumulator 150 (as shown in
In some embodiments, the cyclonic insert 130 may be removably positioned in the cylindrical shell 120. For example, the cyclonic insert 130 may have an outwardly-extending flange 134 at a top of the upper portion 132a that rests upon a recessed seat defined by the flange 123. And one or more anchor bracket 135 may extend inside the cyclonic insert 130 for allowing the cyclonic insert 130 to be lifted into and out of the cylindrical shell 120. More particularly, as shown in
To keep the cyclonic insert 130 from undesirably rotating and assure that the inlet 132d aligns with the inlet opening 126, the flange 134 may have a notch 134a complementary to a protrusion or dowel pin in the flange 123. In addition, a gasket below and/or above the flange 134 may help seal and lock the cyclonic insert 130 via friction when the flange 124 is secured to the flange 123.
While the cyclonic insert 130 may be manufactured in various ways, it has been unexpectedly beneficial to flow patterns to machine two parts piloted and welded together (one for the upper portion 132a and another that forms both the funnel portion 132b and the choke area 132c), weld the flange 134 to the upper portion 132a, and then machine again.
Turning now to the accumulator 150, the accumulator 150 is generally spherical and has upper and lower ends 152a, 152b and inner and outer faces 152c, 152d. The upper end 152a has an opening 153 centered along the longitudinal axis 120′, and the lower end 152b has an exit opening 154 centered along the longitudinal axis 120′. As shown in
It may be particularly important that the inside of the accumulator 150 is substantially open, such that there is no obstruction between the choke area 132c of the cyclonic insert 130 and the exit opening 154 of the accumulator 150 and sand (or other particulate matter) can pass unimpeded and accumulate in the accumulator 150.
The reinforcement pad 170 has an opening 171 centered along the longitudinal axis 120′ and is curved to correspond with the curvature of the accumulator outer face 152d. The reinforcement pad 170 may strengthen the attachment between the accumulator 150 and the cylindrical shell 120, and/or may aid in aligning the accumulator 150 with the cylindrical shell 120 during manufacturing. The reinforcement pad 170 may also be used for aesthetic purposes, and can take various forms.
In use, piping delivers (under high pressure) fluid and particulates from oil and gas extraction operations to the inlet opening 126 (via the attachment flange 128), and the fluid and particulates pass from the inlet opening 126 to inside the cylindrical wall 122 above the vortex finder lower end 125b. The positioning of the inlet opening 126 causes the fluid and particulates to rotate inside the cylindrical wall 122 in a cyclonic or helical manner, and gravity causes the particulates to filter through the cyclonic insert 130. A low pressure area at the center of the cyclone allows lighter fluids and gasses to rise up into the vortex finder 125 and exit the cylindrical shell 120. The shape and location of the cyclonic insert 130 may be particularly useful in allowing the particulates to pass through the funnel portion 132b and the choke area 132c while causing the fluid to exit through the vortex finder 125 (and ultimately through piping coupled to the vortex finder 125). The particulates passed through the cyclonic insert 130 are accumulated in the accumulator 150 and selectively output through the exit opening 154 using a dumping valve. The skid 110 may provide a convenient, robust package for delivering and moving the other components, and may allow easy access to various components of the sand trap 100.
In some embodiments, as shown throughout the drawings, a filter 200 may be placed downstream of the sand trap 100 in a vertical orientation such that the filter 200 is located on the skid 110. In other embodiments incorporating the filter 200, the filter 200 may be on another skid or otherwise mounted externally to the skid 110. The filter 200 may be used to remove small particles passed through the sand trap 100.
Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims.
Claims
1. A sand trap for use in oil and gas extraction operations, the sand trap comprising:
- a hollow cylindrical wall having upper and lower ends and a longitudinal axis extending generally vertically, the hollow cylindrical wall having an inlet opening for receiving a high pressure fluid stream with particulates, the inlet opening having an axis generally perpendicular but askew to the longitudinal axis of the hollow cylindrical wall;
- a cap selectively secured over the hollow cylindrical wall;
- a vortex finder extending downwardly from the cap and defining a passageway for fluid to exit, the passageway being coaxial with the longitudinal axis of the hollow cylindrical wall;
- a cyclonic insert inside the hollow cylindrical wall; the cyclonic insert having a generally cylindrical upper portion, a choke area, and a funnel portion that narrows from the upper portion to the choke area; the generally cylindrical upper portion having an inlet that is at least as big as the inlet opening and is configured to align with the inlet opening to allow uninterrupted flow into the cyclonic insert; and
- a spherical accumulator extending downwardly from the hollow cylindrical wall, the spherical accumulator having upper and lower ends and a center axis that is coaxial with the longitudinal axis of the hollow cylindrical wall, the spherical accumulator upper end having an upper opening centered along the longitudinal axis of the hollow cylindrical wall, the spherical accumulator lower end having an exit opening centered along the longitudinal axis of the hollow cylindrical wall, the spherical accumulator being unobstructed from the upper opening to the exit opening such that the particulates are allowed to pass unimpeded and accumulate in the accumulator.
2. The sand trap of claim 1, wherein the lower end of the hollow cylindrical wall passes through the upper opening of the spherical accumulator and into the spherical accumulator.
3. The sand trap of claim 2, wherein:
- the cyclonic insert upper portion, funnel portion, and choke area have a generally constant wall thickness;
- a support extends from the choke area to the cylindrical wall;
- the spherical accumulator meets the cylindrical wall along a ring formed in a generally horizontal plane; and
- the support meets the cylindrical wall along the generally horizontal plane.
4. The sand trap of claim 2, wherein the choke area of the cyclonic insert extends below an upper point on the spherical accumulator.
5. The sand trap of claim 4, wherein a lower end of the vortex finder extends into the funnel portion of the cyclonic insert.
6. The sand trap of claim 5, wherein the lower end of the hollow cylindrical wall extends below the choke area of the cyclonic insert.
7. The sand trap of claim 1, further comprising a reinforcement pad having an opening centered along the longitudinal axis of the hollow cylindrical wall, the hollow cylindrical wall passing through the reinforcement pad opening, the reinforcement pad being curved to correspond with a curvature of the spherical accumulator, the reinforcement pad being fastened to the hollow cylindrical wall and the spherical accumulator.
8. The sand trap of claim 1, wherein the cyclonic insert is removably coupled to the hollow cylindrical wall.
9. The sand trap of claim 8, wherein:
- a flange extends from the hollow cylindrical wall upper end;
- the cap is selectively secured to the flange;
- the flange defines a recess; and
- a top of the cyclonic insert upper portion is seated in the recess of the flange.
10. The sand trap of claim 9, wherein the top of the cyclonic insert upper portion has a notch complementary to a protrusion in the flange.
11. The sand trap of claim 9, wherein the cyclonic insert upper portion has an anchor bracket above the inlet of the cyclonic insert for allowing the cyclonic insert to be lifted into and out of the cylindrical shell.
12. The sand trap of claim 1, further comprising:
- a skid having a base, a post, and a joist;
- a stand extending upwardly from the skid base and supporting the spherical accumulator; and
- bracing coupling the hollow cylindrical wall to at least one item selected from the group consisting of the post and the joist;
- wherein a generally horizontal plane extends along the inlet opening axis,
- wherein the bracing extends along the generally horizontal plane; and
- wherein the skid is movable between a generally horizontal position for transport and a generally erect position for use.
13. The sand trap of claim 1, further comprising a downstream vertical filter.
14. The sand trap of claim 13, wherein the downstream vertical filter is offset laterally from the spherical accumulator.
15. The sand trap of claim 1, wherein an outer diameter of the spherical accumulator is smaller than a length between the upper and lower ends of the cylindrical wall.
16. The sand trap of claim 15, wherein an inner diameter of the choke area is larger than an inner diameter of the vortex finder.
17. The sand trap of claim 1, wherein a length of the vortex finder is greater than a length of the cylindrical upper portion of the cyclonic insert.
18. The sand trap of claim 1, wherein the funnel portion and choke area of the cyclonic insert are collectively longer than the cylindrical upper portion of the cyclonic insert.
19. A sand trap for use in oil and gas extraction operations, the sand trap comprising:
- a cyclonic flow section having a longitudinal axis, an inlet opening for receiving a high pressure fluid stream with particulates, a generally cylindrical upper portion, a choke area, and a funnel portion that narrows from the upper portion to the choke area; the inlet opening having an axis generally perpendicular but askew to the longitudinal axis;
- a cap over the cyclonic flow section;
- a vortex finder extending downwardly from the cap and defining a passageway for fluid to exit, the passageway being coaxial with the longitudinal axis; and
- a spherical accumulator extending downwardly from the cyclonic flow section, the spherical accumulator having upper and lower ends and a center axis that is coaxial with the longitudinal axis, the spherical accumulator upper end having an upper opening centered along the longitudinal axis, the spherical accumulator lower end having an exit opening centered along the longitudinal axis, the spherical accumulator being unobstructed from the upper opening to the exit opening such that the particulates are allowed to pass unimpeded and accumulate in the accumulator.
Type: Application
Filed: Aug 4, 2021
Publication Date: Apr 28, 2022
Inventors: Cody Steven Moore (Evanston, WY), Jeremy Myers (Calgary)
Application Number: 17/444,442